Status of Resonant Diplexer Development for high-power ECRH Applications

Characteristics of ring resonator diplexers for high-power ECRH are briefly reviewed. Commissioning experiments performed on ASDEX Upgrade with the diplexer Mk IIa are presented, which demonstrate slow and fast switching of the power between two launchers, and thus the capability for efficient suppression of neoclassical tearing modes and simultaneous central heating of the plasma. The development of the compact diplexer Mk IIIb is discussed, and test results are presented. Finally, an evacuated design for 170 GHz is shown.